Process for lubricating filaments



nite tates atent 2,904,454 PROCESS FOR LUBRICATING FILAMENTS FranzBerndt, Kassel-Bettenhausen, and Wilhelm Sonnenschein, Kassel, Germany,assignors to Spinnfaser Aktiengesellschaft, Kassel-Bettenhausen, GermanyNo Drawing. Application October 12, 1955 Serial No. 540,171

Claims priority, application Germany October 15, 1954 7 Claims. (Cl.117- 1395) This invention relates to finishing of filaments and to a newand improved finishing process.

In the manufacture of artificial filaments such as threads and fibers,finishing materials are applied. Usually, this application is made afterspinning and deacidifying, desulfurating, bleaching, washing the threadsor fibers, by rinsing or spraying them with or passing them through afinishing bath. Thereafter, the greatest part of the adhering liquid isremoved mechanically, as by centrifuging or squeezing so that in thedrying process which follows, it will not be necessary to evaporateexcessively large quantities of Water. In these processes, a large lossof finishing substances cannot be avoided. Furthermore, employing thesefinishing processes, the later operations often were unsatisfactory. I

It is therefore an object of the invention to provide a new and improvedprocess or method for finishing filaments with the usual finishingcompositions e.g. sulfonates of tallow, esters of polyglycols and fattyacids, emulsions of mineral oils, or mixtures of these components.

A particular object is to provide a process which reduces the losses offinishing substances.

Another object is to provide a finishing process which improves thesubsequent operations, e.g. coiling rayon filaments or producing yarnsfrom staple fibers.

An additional object is to provide a process wherein filaments aresimultaneously or concurrently finished and moisture-conditioned, sothat they have the desired moisture or Water content. v

Another object is to provide a flexible two-stage finishing process,wherein drying of the filaments may take place between the finishingstages or subsequent to both stages, as desired.

A more particular object is to provide a process wherein a relativelyvery dilute aqueous finishing emulsion is first applied to thefilaments, the emulsion being very dilute as compared to the standard orprior emulsions applied, so that losses of the emulsion representreduced losses of the finishing substances corresponding to theirdecreased concentration, and then a relatively concentrated aqueousfinishing emulsion is applied for precise application to the filamentswithout losses, to provide on the filaments the quantity of finishingsubstances required for satisfactory execution of the subsequentoperations. These and other objects and advantages of the invention willbe apparent on reference to the specification.

In accordance with the invention, it has now been found that byeffecting the finishing in two steps or stages considerable quantitiesof finishing materials are saved in comparison with previously knownprocesses, and also, considerable improvements are obtained in thesubsequent manufacturing operations. In the invention, the filaments aretreated or contacted following to the-washing process with a dilutefinishing liquid composition, excess liquid is mechanically separated,and the filaments are treated with a concentrated finishing liquidcomposition.

. The first application is with a .composition which is.

dilute relative to the compositions usually employed for finishing,which contained e.g., 2-10 grams per liter, and it contains thefinishing substances in a concentration of about 0.020.2 g./l.preferably 0.1 to 0.2 grams per liter. The second application is with afinishing composition or concentrate which is relatively concentratedwith respect to the usual finishing compositions applied, and there arepreferably about 70 to 200 grams per liter of finishing substances inthe concentrate. The concentration is selected within this rangeaccording to the desired amount of finishing application and the desiredamount of moisture-conditioning. The mechanical separation of excessliquid subsequent to the first application preferably takes place bycentrifuging or squeezing, with no concentration such as by drying.

The filaments are dried either between the two finishing stages ortreatments, following the mechanical separation of excess liquid, orfollowing both of them. In either event, the usual volume of finishingliquid composition is applied in the first stage, but the concentrationis much less than usual. When drying takes place intermediate thefinishing applications, the second finishing is preferably carried outso that the filaments are simultaneously moisture-conditioned withoutemploying and with no necessity for a subsequent drying or moisteningoperation. Operating in this manner, the concentration of the secondfinishing composition is adjusted so as to impart the desired moisturecontent to the filaments while applying the desired amount of finishingsubstances. The total amount of finishing substances applied in thefirst and second stages corresponds to that usually applied in oneoperation according to the prior processes. The application of thedilute composition is as before, by rinsing or spraying or passingthrough a finishing bath. The second finishing composition may beapplied after drying by spraying, rinsing or moistening with moistrollers.

With intermediate drying, it is unnecessary to provide and use amoistening zone with the dryer, because the moisture-conditioning iscombined in the second finishing step.

If simultaneous moisture-conditioning of the filaments is not desired,the two finishing stages can be carried out in the absence of a dryingoperation or prior to drying, with intervening mechanical separation ofexcess liquid as described above, and the filaments thus processed aremore advantageously employed in the subsequent operations than whenoperating according to the prior procedures. The resulting yarn is moreuniform. After applying the second, concentrated finishing composition,the filaments are dried, the drying being carried out employing theusual moistening zone.

The finishing conditions are those conventionally employed, with thedescribed new conditions according to the invention. The compositionsare applied either at about room temperature, about 15-25 C., or atabout 5060 C., depending upon the finishing materials. The dryingconditions are those usually employed e.g. in

streaming dry air of a temperature of about 50120 C.-

and up to a rest moisture content of 5%.

The process of this invention is suitable for every kind of artificialfilaments, such as filaments and staple fibers of regenerated cellulose,casein or alginates. Naturally, the kind of finishing material must beadjusted to the kind of filament, thickness, intended use, etc. IfStaple fibers are concerned, the first step of the process is carriedout with the usual finishing machinery. The second step of the processis carried out while the more or less open staple fiber fleece leavesthe dryer. It is also possible to insert this second step between thedryer and the packing of the staple fibers, for instance after theopening operation.

V 2,904,454 p A thread cable groups are concerned, the first operatingstep can be carried out in the same manner as in the case of staplefibers by spraying, rinsing, or passing through a finishing bath. Thesecond step also can be carried out before or after the dryingoperation. In the case of thick cables it is necessary to lay themout'wid'e during the second step in order to obtain even distribution ofthe finishing material. It is advantageous to use moistening rollers inthe case of cables, thread groups, etc.

The following examples are furnished to illustrate the invention, and itis to be understood that the invention is not limited thereto nor theparticular materials, proportions and conditions set forth therein.

Example 1 A fiber fleece of regenerated cellulose is rinsed after thedeacidifying, desulfurating, bleaching and washing process with afinishing bath containing 0.1 to 0.2 grams per liter of finishingmaterial, as sulfonate of tallow, at 50 to 60 C. Excess liquid isseparated from the filaments by centrifuging to a moisture content of120 to 130%, and the filaments are then dried without the use of amoistening zone. At the exit from the dryer, the fiber fleece is sprayedwith a finishing emulsion concentrate of 50 grams per liter of roomtemperature, the concentrate consisting of /3 of sulfonate of tallow and/3 of polyglycol ester of stearine acid. When'the dryer has an hourlycapacity of 500 kg. of fiber, 23.3 liters of finishing emulsion aresprayed per hour, which increases the moisture content from 6% to 11%and applies 0.25% by weight of finishing substances in this step. Afterthis a yarn is produced in the usual manner, which is distinguished byan excellent uniformity.

Example 2 A fiber fleece is finished, as in Example 1, following to theWashing operation with a dilute finishing bath containing 0.1 to 0.2gram per liter of finishing material at 50 to 60 C. After squeezing thefiber fleece to a moisture content of 120 to 130%, the fleece is passedthrough a pair of rollers on which is applied a finishing emulsion of100 grams per liter, containing sulfonate of tallow and /3 polyglycolester of stearine acid, at 50 to 60 C. in such a quantity that 0.2 kg.of finishing substances are applied on 100 kg. of fiber. Thereafter, thefilaments are dried in the usual manner.

Example 3 A thread cable of 300,000 denier of regenerated cellulose ispassed after leaving the washing trough through a bath containing 0.1 to0.2 gram per liter of finishing material, as sulfonate of tallow, at 50to 60 C. and it is then squeezed and dried to 6% moisture contentwithout the use of a moistening zone. At the exist from the dryer, thethread cable is passed over a spreading roller and then finished withmoistening rollers at room temperature with a finishing compositionconsisting of /3 sulfonate of tallow, /3 of polyglycol ester of stearineacid and /3 of mineral oil. When 150 kg. of cable pass through the dryerper hour, 7.1 liters of finishing emulsion having a concentration of 55grams per liter is applied per hour, raising the moisture content from6% to 11% and applying 0.25 of finishing substances.

The invention thus provides a new and improved twostage finishingprocess which results in substantial savings of finishing substances andprovides improvements in the operations. in a preferred embodiment, thefilaments may be moisture-conditioned simultaneously with application ofthe finishing substances. The process is adaptable to intervening orsubsequent drying, and the two stages combine very advantageously toreduce losses while providing effective application of the finishingsubstances.

The invention is hereby claimed as follows:

1. In a process for lubricating artificial filaments after' the washingoperation following spinning wherein the lubricants are applied to thefilaments in a dilute aqueous liquid composition of the lubricantsfollowed by mechanical separation of excess liquid, the improvementwhich comprises dividing said application of lubricants into two stages,the first said stage comprising the application of said lubricants in adilute aqueous liquid cornposition substantially more dilute than thefirst-mentioned aqueous composition, the second said stage comprisingthe application of said lubricants in an aqueous liquid compositionsubstantially more concentrated than the first-mentioned aqueouscomposition, the total amount of said lubricants applied in said firstand second stages being substantially equivalent to the amount appliedby the first-mentioned aqueous composition, and mechanically separatingexcess liquid from the filaments solely be tween said stages, saidsecond stage application being made in a controlled quantity of acomposition of suflicient concentration to provide the required amountof lubricants on the filaments without mechanical separation of liquid,the losses of lubricants consequently being reduced owing to theirreduced concentration in the liquid losses which accompany said solemechanical separation between stages.

2. The process as defined in claim 1 wherein said fila ments are driedbetween said stages and following said separation of excess liquid, andthe concentration and quantity of said second stage composition are suchas to impart the desired moisture content to said filaments.

3. The process as defined in claim 1 wherein said filaments havingfinishing materials applied thereto are first dried following saidsecond stage.

4. In a process for lubricating artificial filaments after the washingoperation following spinning wherein the lubricants are applied to thefilaments in a dilute aqueous liquid composition containing on the orderof 2-10 grams of the lubricants per liter followed by mechanicalseparation of excess liquid, the improvement which comprises dividingsaid application of lubricants into two stages, the first said stagecomprising the application of said lubricants in a dilute aqueous liquidcomposition containing 0.02 to 0.2 gram of the lubricants per liter, thesecond said stage comprising the application of said lubricants in anaqueous liquid composition containing 50 to 200 grams of the lubricantsper liter, the total amount of said lubricants applied in said first andsecond stages being substantially equivalent to the amount applied bythe first-mentioned aqueous composition, and mechanically separatingexcess liquid from the filaments solely between said stages, said secondstage application being made in a controlled quantity of a compositionof sufficient concentration to provide the required amount of lubricantson the filaments without mechanical separation of liquid, the losses oflubricants consequently being reduced owing to their reducedconcentration in the liquid losses which accompany said sole mechanicalseparation between stages.

5. The process as defined in claim 4 wherein said filaments are driedbetween said stages and following said separation of excess liquid, andthe concentration and quantity of said second stage composition are suchas to impart the desired moisture content to said filaments.

6. The process as defined in claim 4 wherein said filaments havingfinishing materials applied thereto are first dried following saidsecond stage.

7. In a process for lubricating artificial filaments after the washingoperation following spinning wherein the lubricants are applied to thefilaments in a dilute aqueous liquid composition containing on the orderof 2-10 grams of the lubricants per liter followed by mechanicalseparation of excess liquid, the improvement which comprises dividingsaid application of lubricants into two stages, the first said stagecomprising the application of 5 containing 0.02 to 0.2 gram of thelubricants per liter, the second said stage comprising the applicationof said lubricants in an aqueous liquid composition containing 50 to 200grams of the lubricants per liter, the total amount of said lubricantsapplied in said first and second stages being substantially equivalentto the amount applied by the first-mentioned aqueous composition, andmechanically separating excess liquid from the filaments solely betweensaid stages, said second stage application being made by rollers in acontrolled quantity of a composition of suificient concentration toprovide the required amount of lubricants on the filaments withoutmechanical separation of liquid, the losses of lubricants consequentlybeing reduced owing to their reduced concentration in the liquid losseswhich accompany said sole mechanical separation between stages.

References Cited in the file of this patent UNITED STATES PATENTS

1. IN A PROCESS FOR LUBRICATING ARTIFICIAL FILAMENTS AFTER THE WASHINGOPERATION FOLLOWING SPINNING WHEREIN THE LUBRICANTS ARE APPLIED TO THEFILAMENTS IN A DILUTE AQUEOUS LIQUID COMPOSITION OF THE LUBRICANTSFOLLOWED BY MECHANICAL SEPARATION OF EXCESS LIQUID, THE IMPROVEMENTWHICH COMPRISES DIVIDING SAID APPLICATION OF LUBRICANTS INTO TWO STAGES,THE FIRST SAID STAGE COMPRISING THE APPLICATION OF SAID LUBRICANTS IN ADILUTE AQUEOUS LIQUID COMPOSITION SUBSTANTIALLY MORE DILUTE THAN THEFIRST-MENTIONED AQUEOUS COMPOSITION, THE SECOND SAID STAGE COMPRISINGTHE APPLICATION OF SAID LUBRICANTS IN AN AQUEOUS LIQUID COMPOSITIONSUBSTANTIALLY MORE CONCENTRATED THAN THE FIRST-MENTIONED AQUEOUSCOMPOSITION, THE TOTAL AMOUNT OF SAID LUBRICANTS APPLIED IN SAID FIRSTAND SECOND STAGES BEING SUBSTANTIALLY EQUIVALENT TO THE AMOUNT APPLIEDBY THE FIRST-MENTIONED AQUEOUS COMPOSITION, AND MECHANICALLY SEPARATINGEXCESS LIQUID FROM THE FILAMENTS SOLELY BETWEEN SAID STAGES, SAID SECONDSTAGE APPLICATION BEING MADE IN A CONTROLLED QUANTITY OF A COMPOSITIONOF SUFFICIENT CONCENTRATION TO PROVIDE THE REQUIRED AMOUNT OF LUBRICANTSON THE FILAMENTS WITHOUT MECHANICAL SEPARATION OF LIQUID, THE LOSSES OFLUBRICANTS CONSEQUENTLY BEING REDUCED OWING TO THEIR REDUCEDCONCENTRATION IN THE LIQUID LOSSES WHICH ACCOMPANY SAID SOLE MECHANICALSEPARATION BETWEEN STAGES.